The present application relates to a device for separating a liquid from a gas stream.
DE 197 20 775 A1 discloses a device for separating a liquid from a gas stream for a crank housing vent. In a filter mat of the device, oil drops are separated from a blow-by gas. The oil separated in the filter mat runs downward by a low blow-by gas volume stream based on the force of gravity through the filter mat and drops off the filter mat. With a high blow-by gas volume stream, the liquid separated in the filter mate is carried off by the blow-by gas. In this manner, newly formed drops are generally larger than previously, so that they immediately fall off on a refined gas side. There, oil is collected on the refined gas side of the filter mat. Because of a stream pressure of the blow-by gas, the oil only can run with a still internal combustion engine or with very low blow-by gas volume stream back on a crude gas side of the filter mat. If the oil level increases to the refined gas side, since the oil cannot run off, the danger exists that the filter surface is clogged partially by oil, the collected oil is carried off by the blow-by gas, is carried to an intake manifold of the internal combustion engine, and is burned in the internal combustion engine, which naturally represented a oil loss that is to be avoided. In addition, the oil component, such as, for example, hot film anemometer, turbo charger, and the supercharger intercooler in the intake manifold and other aggregates, can be damaged.
The oil collected on the refined gas site can be returned via a refined gas site oil return into a crank housing, such as, for example shown in DE 197 20 775 A1 or DE 196 45 666 A1. Since a pressure difference exists between the crank housing and the refined gas side of the device, a short circuit current through the oil return from the crank housing on the refined gas side is to be avoided. For this purposed, a siphon can be used, for example. It is disadvantageous on a refined gas side oil return that the pressure difference between the crank housing and the refined gas side of the device is greater than the pressure difference between the crank housing and the crude gas side of the device, so that also the siphon must have a greater length and requires more structural space.